Honor Harrington's Universe

Date"conversion"problems

I have noticed inconsistencies between day length, year length,
number of days per year, etc.
The problem is that Weber's numbers (More Than Honor p.336)
contradict each others.
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With my assumptions (taken from MTH p. 335-337)
- March 21, 1416 PD equals First 1, 1 AL (Manticoran style).
- March 3, 1900 PD equals Fourth 25, 280 AL.
- The Manticoran year is 673 local days, with every third a
leap year of 674 days.
- The Manticoran year has 18 months of 37 or 38 days each.
I get these numbers for length of Manticoran year and day:
The Manticoran year is 1.7333 T-years,
or 633.0831 T-days,
or 673.3333 M-days.
The Manticoran day is 0.9402 T-days,
or 22.5653 hours,
or 22 hours 33.9203 min,
or 22 hours 34 minutes.
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David Weber has stated (the table p. 336 in MTH) that the
Manticoran year is 673.31 M-days, to get close to that we
need a more complicated leap year rule.
If we assume that every 3:rd year, except those divisible
by 42 is a leap year, we get these numbers for length of
Manticoran year and day:
The Manticoran year is 1.7333 T-years,
or 633.0803 T-days,
or 673.3111 M-days.
The Manticoran day is 0.9403 T-days,
or 22.5661 hours,
or 22 hours 33.9635 min,
or 22 hours 34 minutes.
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But to get a Manticoran day of 22.45 hours (22 h, 27 m) the
M-year needs to be 676.8 M-days long.
And assuming that landing did not happen at 01-01-01 AL, but
late in year 1 AL does not help, because that will actually
make the M-day longer.
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We might instead assume that the M-day is exactly 22.45 hours,
and ignore that 280-04-25 AL is supposed to equal 1900-03-03 PD.
Then 280-04-25 AL will equal 1897-09-11 PD, and we get these
numbers for length of Manticoran year and day:
The Manticoran year is 1.7245 T-years,
or 629.8472 T-days,
or 673.3333 M-days.
The Manticoran day is 0.9354 T-days,
or 22.4500 hours,
or 22 hours 27.0000 min,
or 22 hours 27 minutes.
----------------------
If we instead assume that David Weber has used a year zero AL
in his calculation, we get much closer to the numbers in MTH:
The Manticoran year is 1.7271 T-years,
or 630.8215 T-days,
or 673.3333 M-days.
The Manticoran day is 0.9369 T-days,
or 22.4847 hours,
or 22 hours 29.0836 min,
or 22 hours 29 minutes.
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So one can see that there are inconsistencies.
// 1998-10-05 Bo Johansson